(1) FIELD OF THE INVENTION
This invention relates to suction devices for a two-cylinder internal combustion engine, and more particularly it is concerned with a suction device suitable for use with a two-cycle, two-cylinder internal combustion engine of the crankcase precompression type having at least one reed valve which is used with a power-driven machine, such as a chain saw, a power-driven sprayer, etc.
(2) DESCRIPTION OF THE PRIOR ART
Engines used with power-driven machines should meet the requirements of being compact in size, light in weight and high in output power while being minimized in vibration. One type of engine which best meets these requirements is a two-cycle internal combustion engine of the crankcase precompression type having at least one reed valve which has two cylinders located horizontally in face-to-face relation. In this type of two-cylinder, two-cycle internal combustion engine, it has hitherto been necessary to provide the engine with one reed valve of a larger size or a plurality of reed valves arranged in side-by-side relation to allow a sufficiently large amount of air-fuel mixture to be drawn by suction into a crankcase when the displacement volume of the engine is large. When this step is taken, the suction device becomes large in size. Additionally, the effective volume of the crankcase increases, with a result that difficulties might be experienced in performing satisfactorily precompression of the air-fuel mixture in the crankcase.